HIM vs Oly overall training intensity

Am several weeks into training for my first HIM (Big Kahuna in Santa Cruz in September), and I'm noticing that my workout intensity is dramatically different than my Oly intensity. Yes, the volume is higher as well, at least for the bike, but the run it's not so different. I've done 2 -3 Olys a year in the past 3 years, and am now using an adapted version of the trinewbies intermediate HIM Plan which I'm finding is too light on the running but plenty heavy on the bike. (40 mile midweek rides are hard to work in!)

I'm pretty much living in zone2, and dropping into zone3 on steep climbs, but just brushing the lower end of lactate threshold territory.

In contrast, most of my Oly workouts were pain, pain and more pain with lots of intensity.  Yes, most of the workouts were under 90 minutes long, so it was possible to do that, whereas if you're on a 3 hour bike ride, that's unsustainable. Thus far, due to the intensity difference, the HIM workouts are a lot easier, but just harder to fit into the day due to logistics of time spent.

How have your oly vs HIM training regimens compared?